Floor polishing and scrubbing machine



March 19, 1957 A. J. M MASTER ETAL 2,785,424

& FLOOR POLISHING AND SCRUBBING MACHINE Filed Nov. 27. 1950 8 Sheets-Sheet l IN VEN TORS March 19, 1957 A. J. M MASTER ETAL 2,735,424

FLOOR POLISHING AND SCRUBBING MACHINE Filed Nov. 27, 1950 8 Sheets-Sheet 2 March 19, 1957 A. J. MCMASTER ET AL 2,785,424

FLOOR POLISHING AND SCRUBBING MACHINE Filed Nov. 27, 1950 8 Sheets-Sheet 3 -INVENTOR$. ammekmmasw March 19, 1957 A. J. M MASTER ETAL 2,785,424

FLOOR POLISHING AND SCRUBBING MACHINE Filed NOV. 27, 1950 8 Sheets-Sheet 4 i fyj g 16 HHIHU INVENORS.

March 19, 1957 A. J. MOMASTER ET AL 2,785,424

FLOOR POLISHING AND SCRUBBING MACHINE Filed Nov. 27, 1950 8 Sheets-Sheet 5 March 19, 1957 A. J. M MASTER ET AL FLOOR POLISHING AND SCRUBBING MACHINE Filed NOV. 27, 1950 a Sheets-Sheet 6 6 r q z 5 w a 4 6 7 wm 6 j .l V& 6 x J/ J s 5% 3 a J V w L J Z J j J 4% L 1. 3 &,V\/./ j g g 3M 75 8 010%; "m l M 5 A M fi J W March 19, 1957 A, J, MCMASTER ETAL 2,785,424

FLOOR pousame AND SCRUBBING MACHINE Filed Nov. 27, 1950 s Shets-Sheet 7 J50 nlIlII' I mm- 5%.

INVENTORS 5) TMMV March 19, 1957 A. J. MOMASTER ETAL 2,785,424

FLOOR POLISHING AND SCRUBBING MACHINE Filed Nov. 27, 1950 8 Sheets-Sheet 8 E03 19.9 j {95/ 5% w -I v J95 i INVENTORS. a/l/asier United States Patent '0 2,785,424 FLOOR POLISHING AND SCRUBBING MACHINE Archie J. McMaster, Bannockburn, Deerr'ield, William H.

Kitto, Evanston, and Kurt Burian, Chicago, 111., assignors to G-M Laboratories, Inc., Chicago, 111., a corporation of Illinois Application November 27, 1950, Serial No. 197,725 24 Claims. (CI. 15-49) This invention relates to a floor polishing and scrubbing machine and more particularly to such a machine having a single rotary fiat brush which normally supports the weight of the machine.

The principal object of this invention is to provide an improved floor polishing and scrubbing machine which has relatively high polishin and scrubbing efficiency, which is relatively small and compact in construction, which is relatively light in weight, which may be readily and easily manipulated and controlled, in which oscillations and gyraticns of the machine are substantially eliminated, which may be inexpensively manufactured and readily serviced, which has long life under normal operating conditions, which may be readily started, which will not overheat or burn out in the event of stalling of the brush, and which will not mar furniture or floors.

The improved floor polishing and scrubbing machine of this invention includes a base member which is preferably of an inverted cup shaped configuration. A substantially constant speed single phase induction motor is mounted on the upper side of the base member with the motor shaft extending downwardly through the base memher. A phasing reactor is also mounted on the upper side of the base member. A cover is secured to the upper side of the base member and encloses the motor and phasing reactor. The lower end of the motor shaft operates a motor pinion meshing with a cluster gear carried by a bracket secured to the lower side of the base member. The cluster gear also meshes with an output gear carried by a bracket also secured to the lower side of the base member. Mounting means detachably secure a flat rotary brush to the output gear to be driven thereby. A centrifugal clutch is located between the motor shaft and the motor pinion. A handle having a bail is pivotally mounted on the side of the frame in transverse alignment with the brush axis for manipulating and controlling the machine.

When the motor is started, it starts under no load and rapidly accelerates to a speed at which the motor torque reaches its maximum value. At this point the centrifugal clutch connects the motor through the gearing to the brush for rotating the same at the desired speed. The machine may be readily and easily manipulated and controlled for performing the floor polishing and scrubbing operations. In case the brush should be jammed and fail to rotate on starting or in case the brush should be stalled during use, the centrifugal clutch will permit the motor to operate at substantial speed thereby avoiding overheating and burning out of the motor-under these conditions.

To eliminate oscillation and gyration of the machine while performing the polishing and scrubbing operations, the machine is balanced in weight with respect to the rearwardly and upwardly extending handle. In this regardthe product of the gravitational force on the forward portion of the brush and the distance from that-forward portion of'the br'ush'to the grip portion of the handle is made substantially equal to the product of the gravitational force on the rearward portion of the brush and the distance from that rearward portion of the brush to the grip portion of the handle. 0 make the rear portion of the machine heavier to establish this relation, the phasing reactor is located at the rear of the machine. Also to eliminate oscillation and gyration of the machine, the handle bail is frictionally coupled to the machine and means are provided to increase the friction as the handle is lowered and to decrease it as the handle is raised. By reason of these features the machine may be readily manipulated in desired directions with little or no oscillation or gyration with the least amount of control effort applied to the grip portion of the handle.

The upper side of the cover is provided with a stop just forward of the center of the machine to be engaged by the handle bail when the handle is raised to a point just beyond vertical. This permits the handle to rest securely in a substantially vertical position for storage purposes and also prevents tilting of the machine out of its normal position when being carried from place to place by the handle.

The centrifugal clutch, motor pinion, cluster gear and output gear are all located within the confines of the inverted cup shaped base member and only the polishing or scrubbing brush, when secured in place on the output gear, projects below the base member. The lower edge of the base member is provided with an outwardly and downwardly projecting furniture guard to prevent marring of furniture and to prevent marring of the floors when the machine is placed on the floor with the brush removed.

All of the component parts of the machine are carried by the single base member so that they may all be accurately positioned with respect to each other with a minimum of effort, thereby greatly reducing manufacturing and assembly costs. Further, when the brush and cover are removed, the various parts are exposed for ready inspection, cleaning and repair, if necessary.

The top of the cover is provided with air inlet openings and the top of the base member is provided with air outlet openings. A fan is carried by the upper end of the motor shaft and circulates cooling air from the air inlet openings over and through the motor and out through the outlet openings. Baflies are provided for directing the cooling air to provide maximum cooling of the motor. The cooling air passing through the outlet openings enters the inverted cup shaped base member and then escapes around the periphery of the brush. This cooling air builds up a positive air pressure in the base member and effectively prevents dirt and the like caused by the polishing and scrubbing operations from entering into the base member. In this way the centrifugal clutch, gearing and bearings contained within the base member are kept clean and free from foreign particles. Since the cooling air inlet is at the top of the machine and at a point farthest from the brush, intake of dirt and foreign particles with the cooling air is maintained at a minimum.

The driving motor is of unique construction and provides for great economy in manufacture. it includes a laminated rotor provided with rotor bars and integral cooling fins, the rotor being carried by the motor shaft. It also includes a laminated stator of three parts. One part has a central opening for receiving the rotor and also a plurality of opposed external slots for receiving the motor windings. The motor here illustrated by way of example has four pairs of such external slots. The external slots are provided with suitable slot liners and the coils may be machine wound directly on the stator piece. In this respect the stator piece may be applied to a suitable rotatable winding fixture and rotated about a transverse axis substantially perpendicular to a plane passing through a pair of opposed external slots. In

this way the coil may be machine wound in these opposed external slots. The stator piece may then be shifted similarly to wind coils in the other pairs of external slots. If desired, two sets of coils may be simultaneously wound in adjacent pairs of external slots. This procedure eliminates the necessity of separately winding the coils and then inserting them in the slots and also eliminates the necessity of separate lead wires from the stator coils". Further, the stator coils so formed may be readily, rapidly and inexpensively tied. The other two stator pieces are generally crescent-shaped and overlie the external slots of the first stator piece to complete the magnetic circuit outside the windings. The three stator pieces are automatically clamped into position by a clamping band which forms a part of the stator supporting member. The inner closed portions of thestator slots also aid materially in the distribution of the flux and improve the performance of the motor.

The motor stator supporting member includes a band for clamping the motor stator and is provided with upwardly and downwardly extending legs. The clamping nut may be provided with ears overlying the stator and/ or the legs may be lanced to provide lugs overlying the stator to prevent longitudinal shifting of the stator in the supporting member. The downwardly extending legs are secured to the upper side of the base member. The upwardly extending legs carry a bearing support plate. The base member and the bearing support plate are provided with hearing seats for receiving self-aligning bearings for the motor shaft. In assembling the machine the stator supporting member is loosely secured to the base member, the bearing support plate is loosely secured to the stator supporting member, and the rotor is shimmed with respect to the stator for centering the same. The stator supporting member and the bearing support plate are then tightly secured in place and the shims removed. In this way the rotor is accurately centered in the stator and the necessity for maintaining extremely close tolerances for centering purposes is eliminated. This feature greatly reduces the cost of manufacture of the machine and improves its performance. The motor shaft is also provided with improved thrust bearings cooperating with the motor bearings and the hub of the fan operates as the thrust stop for the upper thrust bearing.

The centrifugal clutch carried by the lower end of the motor shaft includes a drive plate adjustably carried by the motor shaft which in turn carries a plurality of weights urged inwardly by a garter spring. Spring devices between the clutch plate and the weights provide for a resilient drive and eliminate noise. A clutch cup including a suitable lining is engaged by the weightsgwhen the motor spee'd reaches the desired value and is driven thereby. The clutch cup is journaled for relative rotation on the motor shaft and carries a motor pinion, the

motor pinion being coupled to the motor shaft by the centrifugal clutch when the motor is up to speed and uncoupled therefrom when the motor is not up to speed.

The motor pinion meshes with a cluster gear rotatably mounted on a shaft carried by a bracket adjustably secured to the lower side of the base member. The cluster gear meshes with an output gear rotatably mounted on a bracket also adjustably secured to the lower side of the base member. The mounting bracket for the output gear also serves as an outboard support for the cluster gear shaft. In assembling the gearing, the cluster gear is brought into proper meshing relation with the motor pinion and then its supporting bracket is securely fastened in place on the base member. Then the output gear is brought into proper meshing relation with the cluster gear and its supporting bracket is tightly secured to the base member. In this way correct meshing of the gearing is assured and the maintenance of close tolerances in the parts is not required. This further decreases the costs of manufacture of the machine.

The engaging teeth of the motor pinion and cluster gear are helically formed to provide a downward thrust on the motor shaft and an upward thrust on the cluster gear during operation for the purpose of eliminating intermittent thrust motion of the motor shaft and cluster gear and noise which would result therefrom. Suitable thrust bearings are provided for the motor pinion and cluster gear. The engaging teeth of the cluster gear and output gear are regularly formed and since the output gear, which carries the brush, supports the weight of the machine, it is also provided with a thrust hearing.

The gears are all rotatably journaled by means of porous bearings supplied with suitable lubricant and the gears are formed of suitable plastic, such as nylon, for oilless and noiseless operation. As a result the necessity for gear boxes, seals, gaskets and the like is eliminated. The gears are unique in construction in that they include metal body portions, plastic tires having the gear teeth formed therein and novel means for securing the plastic tires to the body portions. The tires in blank form are secured to the body portions and then the gear teeth are hobbed in the plastic tires. This provides fast cutting of accurate gear teeth and eliminates the necessity of maintaining close tolerances in the parts.

The polishing brush is constructed to provide maximum polishing efiiciency and to properly support the machine with the least tendency to cause the machine to oscillate or gyrate during operation. The polishing brush bristles are preferably conically arranged with respect to the axis of rotation of the brush for stability in supporting the weight of the machine. The brush is provided with a disc portion having annular slots of keyhole shape. The output gear is provided with an annular boss and with pins having conical heads. The pins are received in the keyhole slots for causing the disc portion ofthe brush to be drawn against the annular boss of the output gear for firmly and detachably securing the brush tothe output gear. Since the brush forms the sole support for the machine, the drawing of the brush against the annular boss of the output gear squares up the machine and prevents w'obbling. of the machine. A spring detent is provided to maintain the pins in the slots.

When the machine is used as a scrubber rather than a polisher, the resistance to rotation of the brush is less. However, the brush will not unduly speed up, as in other machines of this general type, because of the substantially constant speed characteristics of the motor. Thus, flinging outwardly of soap and water and consequent splashing of furniture, walls and the like are eliminated.

Further objects of this invention reside in the details of construction of the floor polishing and scrubbing ma chine and the cooperative relationships between the component parts thereof.

Other objects and advantages of this invention will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawings, in which: a

Fig. l is a side elevational view of the floor polishing and scrubbing machine of this invention;

Fig. 2 is a front elevational' view looking from the left in Fig. 1;

Fig. 3 is an enlarged top plan view of the machine;

Fig. 4 is a partial sectional view taken along the line 4-4 of- Fig. 3",

Fig. 5 is an enlarged vertical sectional view taken through the machine;

Fig. 6 is a partial elevational view looking from the inside of the machine, showing the manner in which the handle bail is secured to the machine;

Fig. 7 is a horizontal sectional view taken along the line 7--7 of Fig. 6';

Fig. 8 is a vertical sectional view taken along the line 8-'-8 of Fig. 6;

. Fig. 9 is a partial bottom view showing the manner of applying the brush to the machine;

Fig. 10 is a view similar to Fig. 9 but showing the brush secured in place;

Fig. 11 is a perspective view of the supporting bracket for the output gear;

Fig. 12 is a partial sectional view of another form of output gear supporting bracket;

Fig. 13 is a bottom view of the machine with the brush removed;

Fig. 14 is a top plan view of the motor stator;

Fig. 15 is a side elevational view of the motor stator;

Fig. 16 is an exploded view of the laminations forming the stator;

Figs. 17 and 18 are diagrammatic illustrations showing the manner of winding the coils on the stator;

Fig. 19 is a schematic wiring diagram of the motor;

Fig. 20 is a top plan view of the assembled motor stator;

Fig. 21 is a side elevational view of the assembled motor stator;

Fig. 22 is a diagrammatic illustration of the motor stator showing the coil arrangement and the electrical connections thereto;

Fig. 23 is a vertical sectional view through the motor rotor;

Fig. 24 is an end elevational view of the motor rotor;

Figs. 25 and 26 are partial sectional views taken along the lines 2525 and 26-26, respectively, of Fig. 23;

Fig. 27 is a top plan view of the centrifugal clutch;

Fig. 28 is a horizontal sectional view through the centrifugal clutch taken along the line 28-28 of Fig. 29;

Fig. 29 is an enlarged sectional view through the centrifugal clutch taken along the line 29-29 of Fig. 27;

Fig. 30 is a sectional view taken along the line 3030 of Fig. 29 and showing the clutch disengaged;

Fig. 31 is a view similar to Fig. 30 but showing the clutch engaged;

Fig. 32 is an exploded perspective view of the centrifugal clutch;

Fig. 33 is an exploded perspective view of the clutch drive plate and weights driven thereby;

Fig. 34 is an exploded perspective view of the clutch -cup assembly;

Fig. 35 is a sectional view taken along the line 35-35 of Fig. 32;

Fig. 36 is an exploded perspective view of the weight utilized in the clutch;

Fig. 37 is an enlarged sectional view of the cluster gear;

Fig. 38 is a sectional view taken along the line 38--38 of Fig. 37;

Fig. 39 is an exploded perspective view of the cluster gear;

Fig. 40 is a vertical sectional view through the output gear;

Fig. 41 is an exploded perspective view of the parts forming the output gear;

-Fig. 42 is a partial bottom view of the output gear.

Referring first to Figs. 1 to 3, 5 and 13, the floor polishing and scrubbing machine of this invention is generally designated at It and includes an inverted cup-shaped base member formed from sheet steel having a side wall 11 and a top wall 12. The top wall 12 is recessed at 13 and is formed with a central bearing seat 14 having a spherical bearing supporting surface 15. The lower edge of the base member is flared outwardly at 16 for the purpose of receiving a furniture guard 17. The furniture guard may be made of rubber or other suitable material and extends outwardly and downwardly from the lower edge of the base member. The furniture guard prevents marring of furniture and marring of the floors when the machine is placed on the floor with the brush removed.

Motor mounting Mounted on the upper side of the base member is an "electric motor, preferably of the split phase induction type. It includes a stator 20 and a rotor 21 carried by a shaft 22. The stator is carried by a stator support member which is illustrated in more detail in Figs. 5, 20 and 21. The motor support member includes a clamping band 23 for clamping the motor stator. In this respect the clamping band 23 is provided with a pair of ears 24 having suitable holes therethrough, one of the ears being provided with a lug 25. A twin nut member 26 receives screws 27 extending through the holes in the ears 24 for the purpose of clamping the motor stator 20 in place. The nut member 26 is provided with projections 28 which overlie the stator 20 to prevent longitudinal shifting of the stator in the stator support member upon jarring of the machine. The stator support member also includes a plurality of downwardly extending legs 30 and upwardly extending legs 31. These legs may be integrally formed from sheet metal and may be welded to the sheet metal clamping band as at 32. The legs 30 and 31 may also be lanced to provide lugs 29, also overlying the motor stator to prevent longitudinal shifting thereof.

The downwardly extending leg 30 are bent outwardly to provide attaching ears 33 having holes therein for the purpose of securing the motor stator support to the upper side of the base member. Likewise, the upper ends of the upwardly extending legs 3?. are bent outwardly to form attaching cars 34 having holes for the purpose of mounting a bearing support plate. The motor stator support is secured to the upper wall 12 of the base member by means of screws 35 extending through the base memher and attaching ears and by means of nuts 36. The attaching ears 34 of the upwardly extending legs 31 carry an annular baffle plate 38, spacers 39, and a bearing support plate 4 The bearing support plate 40 is located above the bafiie plate 3%; and is cupped at 4.1 for receiving screws 42- extending through the bearing support plate 40, spacers 39, bathe plate 33 and attaching ears 34. The parts are held in assembled relation by nuts 43 cooperating with the screws 42. The baflie plate 38 and bearing support plate 421 are formed from sheet metal. The baffle plate 38 carries inwardly an annular baffie 37 which closely surrounds the windings of the electric motor. In this respect the battle 7 is made of insulating material. so as not to cause shorting of the motor windings. The bearing support plate is provided with a bearing seat 46 having a spherical seating surface 47.

The bearing support plate 40 supports a self-aligning bearing 5th preferably made of sintered porous bronze, the bearing having a spherical surface for engagement with the spherical seat 47 of the bearing plate. The porous bronze bearing 5% is surrounded with an absorbent washer 51 containing oil which feeds through the porous bearing for lubricating the running surfaces between the bearing and the motor shaft. A spring member 52 overlies the absorbent washer 51 and is provided with a spherical bearing seat 53 engaging a spherical surface on the other end of the bearing 50. A conical member 54 secured to the bearing plate 4:) by rivets 55 places a spring tension on the spring member 52 for maintaining the bearing 5% in position on the bearing support plate 40.

The motor bearing construction carried by the base member i identical to that carried by the upper bearing support plate. it includes a self-centering sintered porous bronze bearing 55, an absorbent washer 5'7 containing oil, a spring member provided with a spherical bearing seat 59, and a conical member 60 secured by rivets 61 to the base member tensioning the spring member 58.

In mounting the motor, the stator support member is first loosely secured to the base member and the upper bearing support plate 44 is loosely secured to the stator support member. The rotor is then shimmed in place in the stator for centering the same. During this shimming operation the motor bearings 56 and 56 self center. The stator support member is then securely fastened to the base member and the upper bearing support member is securely fastened to the stator support member. The

'7 shims" are then removed and the rotor is thereby self centered in the stator for free rotation therein. in this way the necessity for maintaining extremely close toleralleles for centering purposes is eliminated.

To limit longitudinal movement of the rotor, the rotor shaft is providedwith upper and lower thrust bearings. The upper thrust bearing includes a metal washer 63 running on the bearing Si). This metal washer is backed by a resilient washer 64 such as cork, the resilient washer 64 being tightly fitted to the motor shaft 22 and enclosed ina cup-shaped member 65 to maintain a friction fit between the resilient Washer and the motor shaft. The cupshaped member 6d is flared outwardly along its edge at 66 to act as a slinger of any oil which tends to pass from the bearing" along the shaft, the oil being returned to the absorbent washer 51. The lower thrust bearing is the same as the upper. it includes a metal washer 67 running agairist the motor bearing 56, a resilient washer 68 and a cup-shaped member 69.

The upper end of the motor shaft carries a fan 72 having fan blades 73. The fan hub 74 receives the motor shaft 22 and is adjustably secured in place thereon by a set screw 75 engaging a recessed portion 75 of the shaft. The fan hub 74 acts as a thrust stop for the upper thrust bearing and limits the downward movement of the rotor and its shaft.

A phasing reactor in the form of a choke is also carried by the upper side of the base member 12. it includes two sets of laminations, E laminations 78 and i laminations St The E laminations are secured together by rivets 79 and the l laminations by rivets 31. The E and I laminations are separated by a fiber plate 83 to form.

a fixed gap therebetween and to provide a more nearly constant current characteristic for line voltage variations. The center leg of the E laminations carries a coil 8 wound on a suitable coil form 35, 86 formed of insulating material. The coil form carries connecting terminals $7. The coil form is securely held in place on the center leg of the E laminations by a wooden wedge 32. The lamina tions are encased in a sheet metal housing 83 suitably secured to the upper side of the base member 12. The forward edges of the housing 88 are provided with cam surfaces 39 which receive a wedge member 96. When the wedge member 9% is forced into place, the E and l laminations are securely clamped together and eliminate the humming or buzzing in the choke. If humming or buzzing of the choke should appear after the machine is in operation, this may be eliminated by merely further tightening the wedge. By applying a small amount of airdry electrical varnish to the junction of the E and l laminations, the necessity for additional clamping means for the end laminations to prevent noise is eliminated. It is here noted that the phasing reactor is located at the rear portion of the machine so as to make the rear portion of the machine slightly heavier than the forward portion.

Cover and ventilation The machine is provided with a cover 92 for enclosing the motor and the phasing reactor. The cover is molded from a suitable plastic as by injection or compression molding. The cover is generally cup-shaped in configuration and has a side wall and a top wall 93. The top Wall 93 is provided with a plurality of concentrically arranged air inlet openings 94 through which cooling air is drawn by the fan 72 for cooling and ventilation purposes. The bottom side of the top wall 93 of the cover is provided with bosses 95 for attaching an annular bafile plate 96 having a central opening 97, the opening 97 forming the eye for the fan 72. The bafile plate 96 is secured in place by screws 98. The cover 92 is also internally provided with an annular shoulder 101 which is adapted to engage the battle plate 38 carried by the stator support member. As shown more particularly in Figs. 4 and 13, the lower edge of the cover 921s provided with a pair of projections 102 to be received in holes 103 in the upper wall 12 of the base member. These projection-s cooperate with the holes to aid in centering the cover 92 with respect to the base member 12. The forward side of the cover 92 is provided with a boss 104 having a screw threaded sleeve 1:15 for receiving a screw 196 to secure the cover to the base member. The cover is also provided with a pair of internal bosses 107 carrying screw-threaded sleeves 198 for receiving studs 199. The studs 169 extend downwardly through holes in the upper wall of the base member and carry nuts 110 also for securing the cover to the base member. In this way the cover may be detachably and securely fastened to the base member for enclosing the motor and phasing reactor. The top of the cover is provided with a stop 109 to be engaged by the handle bail when the handle is elevated to a vertical position.

For cooling and ventilation purposes the recessed portion 13 of the upper wall of the base member is provided with a plurality of holes 112 to form outlet air passages. When the machine is in operation, air is drawn through the inlet openings 94 by the fan '72, the air being directed to the center of the fan by the batflle plate 96. The air delivered by the fan passes around the outside of the upper bearing support plate 46 and then inwardly along the baflle plate 38. The air thus delivered is forced over the windings of the motor, down through and around the motor, and over the phasing reactor. The air then exits through the outlet openings 112 into the inverted cup-shaped base member. It is noted that the holes 112 are located near the windings of the motor so that the air passing through the openings also passes over these windings. in this way maximum cooling and ventilating efliciency for the motor and phasing reactor are obtained. Since the air inlet openings 94 are located in the top of the cover farthest away from the floor polishing operation, the amount of dirt and foreign material drawn into the cover is maintained at a minimum. The baflle plate 96 also hides the fan 72 from view through the openings 94 in the top of the cover.

Motor construction The electric motor including the stator 29, rotor 21, and rotor shaft 22 is illustrated in more detail in Figs. 14 to 26. The motor is of a continuous split phase induction motor type and it is illustrated in this application as a two-pole motor having a pair of main windings and a pair of auxiliary windings. The motor stator 20 includes three sets of laminations, a main set 115 and a pair of crescent-shaped sub-sets 116. The stator lamination has a central opening 117 for receiving the rotor 21. it is externally provided with a pair of recesses 118 for receiving the sublaminations 1.16. The main lamination set includes a plurality of external slots 119426, the slots 119-122 being arranged opposite to the slots 123-126. The portions of the laminations forming the external slots are held together by a thin wall laminated section 128. This thin wall laminated section 128 also operates more efiectively to distribute the flux and enhance the performance of the motor. The main laminations are secured together by rivets 127. The sublaminations 116 have projections 13% engaging the main laminations and the sublaminations are secured together by rivets 131. The sublamination-s operate to complete the magnetic path of the stator. The external slots 119-126 are provided with suitable slot liners 133 made of insulating material.

Because of the external slot arrangement, the motor coils may be machine wound on the stator laminations 115. The manner of so winding the coils is illustrated in Figs. 17 and 18. The stator lamination 115 is placed in a suitable winding fixture to be rotated about the axis XY, which axis is perpendicular to planes passing through the slots 119, and the slots 120, 126. Wire is fed into these slots as the stator lamination 115 is rotated and in this way coils 135 and 136 are machine wound directly on the stator. The coils 135 and 136 form the main windings of the motor. When winding of these coils is completed, then the stator lamination 115 is rotated to a new position illustrated in Fig. 18, wherein planes passing through the slots 121, 123 and 122, 124 are perpendicular to the axis XY of rotation. Coils 137 and 138 are, therefore, wound in the slots 121, 123 and 122, 124. The coils 137 and 138 are the auxiliary coils of the motor. in winding the motor, the same size wire is preferably used for all the coils and also each coil preferably has substantially the same number of turns. The portions of the coils lying exteriorly of the slots are preferably tied as at 140 and are bent over laterally to clear the rotor 21. The ends of the wire forming the coils may be covered with suitable spaghetti 139 and connected to the terminals 87 on the phasing reactor, the phasing reactor thus acting as a terminal board for the electrical connections. As a result of winding the coils on the stator in this manner, the necessity for separate lead wires is eliminated. The physical arrangement of the tied coils is illustrated in Figs. 20 and 21. The locations of these coils is diagrammatically illustrated in Fig. 22. The Wiring of the motor and the reactor is schematically illustrated in Fig. 19. Here it is seen that the main windings 135 and 136 are connected in parallel to each other and to the terminals 87a and 87b. The auxiliary windings 137 and 138 are connected in series with each other and to the terminals 87b and 87c. The phasing reactor 34 is connected across the terminals 87b and 870 and in parallel with the auxiliary windings. The terminals 87a and 87c are connected to a voltage source LL which may be the conventional voltage supply of 105 to 120 volts, 60 cycles, A. C. The motor under normal polishing and scrubbing conditions operates at approxi mately 3300 R. P. M. with a torque of substantially 2 inch pounds. The motor also is capable of starting at voltages less than 100 volts even under polishing load conditions.

The motor rotor 21 includes laminations 142 carried on a sleeve 143, the sleeve being pressed onto the motor shaft 22 and held for rotation therewith by projections 144 formed on the shaft. The projections operate to key the rotor to the shaft. The rotor also includes integral annular rings 145, rotor bars and cooling fins 146 preferably formed of die cast aluminum. The rotor lamina- .tions 142 and stator laminations 115 and 116 are preferably all punched simultaneously from silicon steel in strip form. This eliminates waste of material and assures accuracy of the parts.

Centrifugal clutch The lower end of the motor shaft 22 carries within the base member 11 a centrifugal clutch and motor pinion assembly including a clutch drive plate 150, clutch Weights 151, a clutch cup J's, and a motor pinion 153. The clutch and motor pinion assembly is shown in detail in Figs. 27 to 36. T he clutch drive plate 150 is staked at 155 to a hub 156 which in turn is adjustably secured ,to the motor shaft 22 by means of a set screw 157, the

set screw engaging a reduced portion on the motor shaft. Thus, the cltuch drive plate 150 is carried and driven by the motor shaft 22. The clutch drive plate includes three fingers 158 for the purpose of driving and guiding the clutch weights. The remaining portions 159 of the drive plate 150 support, guide and separate the main clutch weights 151 and auxiliary clutch weights 166.

There are three main clutch weights 151, each of which is substantially sector-shaped but provided with a clearance radius 161 at the inner end thereof. Each sector is provided with a central opening 162 from which is struck downwardly an ear 163. The ear 163 is flared at its end for providing a cumming action. Each main weight is also provided at its outer edge with a downwardly extending shoe 164. There are also provided three auxilthe detents 176.

iary weights 166, each of which is also substantially sector-shaped, having a radius 167 on its inner end, the radius 167 cooperating with the periphery of the hub 156 to limit inward movement of the weights. The auxiliary weight 166 is also provided with a central opening 168 and the connecting web 169 is curved upwardly for the purpose of spacing the outer end of the lower auxiliary weight apart from the outer end of the upper main weight to a distance substantially equal to the thickness of the drive plate 151). This maintains the two weights 151 and .166 in pa licl relation. The upper weights 151 are placed on top of the drive plate and the lower weights are placed underneath the drive plate, the openings 162 and 163 of the two weights being in alignment with the fingers 153 of the drive plate. U-shaped springs 171 having slots on the ends thereof are inserted in the openings 162 and 16b of the main and auxiliary weights and over the fingers 158 of the drive plate 150. The slots 172 receive the inner ends of the main and auxiliary weights 151 and 166 and operate to maintain the inner ends of these weights in engagement with the drive plate 150. The ears 163 of the upper main weights 151 extend downwardly beyond the ends of the fingers 158 and through the openings 163 in the lower auxiliary weights. A garter spring 173 is hooked over these ears 163. The garter spring, therefore, urges the main and auxiliary weights 151 and i 6 inwardly and because of the flared ends on the ears 153 also operates to maintain the curved rib 16% of the auxiliary weight 166 in engagement with the upper main weight 151. Thus, parallel relationship is maintained between the main and auxiliary weights and they are both urged inwardly by the action of the garter spring.

The outer edges of the auxiliary weights 166 engage the inner surfaces of the shoes res oi the main weights so that both sets of weights are moved inwardly by the garter spring 1'73 and therefore operate together. The inward movement of the weigths is limited by the radius 167 of the auxiliary weights 166 engaging the periphery of the hub 156 of the drive plate. When the weights are so moved inwardly the adjacent edges of the auxiliary weights are brought together for the purpose of circumferentially and radially aligning the auxiliary and main weights. This prevents the weights from becoming cocked and hence causes the shoes i64 to assume a substantially circular position. In assembling the clutch mechanism the main weights and auxiliary weights are brought and held together by the spring clips 171. The main and auxiliary weights are then sandwiched over the drive plate with the spring clips engaging the sides of the fingers 158 of the drive plate. The adjacent edges 17% and the radius 167 of the auxiliary weights 166 extend beyond the corresponding edges and radius of the main weights 151, so that the main and auxiliary weights may be readily separated for slipping them over the drive plate in the assembly of the clutch mechanism. The spring clips 171 provide a resilient driving connection in the rotational direction between the drive plate 3.59 and the noise.

The clutch cup 152 is provided. with a side wall 175 against the inner side of which is mounted a clutch lining 177. The clutch lining is held in place in the clutch cup by detents 176 formed on the upper edge of the clutch cup. Since the fric on between the cltuch lining 177 and the side wal 5 of the c.utch cup is greater than the friction of u shoes of the weights, it is not necessary to permanently secure the clutch lining to the clutch cup. All that n eary is to maintain the clutch lining in place and this s accomplished by The center opening or" the clutch cup is provided with recesses 179 for receiving lugs 180 formed on the upper end of the motor pinion 153. Preferably,

J. themotor pinion is .made of suitable plastic material such 'as' nylon and the lugs 18!) and recesses 179 form a drive connection between the nylon motor pinion and the cltuch cup. The plastic motor pinion 153 is pressed onto a metal sleeve 132 which is provided at its bottom with a shoulder 184 to limit downward movement of the motor pinion with respect to the sleeve. The upper portion of the metal sleeve 132 is provided with a'shoulder 182' which receives a collar 181, the collar operating to clamp the clutch cup 152 in driving engagement on the motor pinion 153. When the are thus assembled, the upper end of the metal sleeve is peened over at 183 to hold the parts is assembled relation. The 'peened over portion is ground or otherwise formed flat since it serves as an end thrust member between the sleeve 182 and the clutch plate hub 156.

A sintered porous bronze bearing sleeve 186 is interposed between the metal sleeve 1.32 and the motor shaft 22. The bearing sleeve have a light interference fit with the motor shaft 22 and has a running fit with the metal sleeve182. The porous bearing sleeve 186 is impregnated with a suitable lubricant for lubricating the running fit and the lubricating action is aided by centrifugal force 'on the lubricant afforded by the rotation of the bearing sleeve with the motor shaft.

A thrust bearing for the motor pinion 153 is provided at the lower end of the motor shaft 22. It consists of a washer 187 carried by the motor pinion and a second washer 138 carried by the motor shaft. The washer 188 is held in place by a split washer 139 carried in a suitable groove on the lower end of the motor shaft.

In assembling the machine for the purpose of obtaining proper spacing of the thrust bearings associated with the motor shaft and in obtaining the proper end play in the motor shaft, the motor pinion assembly is brought to its lowermost position with the thrust washers 157 and 188 in engagement. Then the hub 156 of the clutch drive plate 159 is secured to the motor shaft by the set screw 157 to provide the proper clearance between the hub 156 and the fiat peened over portion 183 of the pinion sleeve 132. in this way proper end play is provided for the clutch and motor pinion assembly. The motor shaft 22 is then "moved upwardly to cause the thrust washer 67 to engage the lower end of the lower motor bearing 56. The upper thrust washer 63 is caused to engage the upper surface of the upper motor hearing or The fan hub 7 is then secured to the motor shaft by the set screw '75 to provide proper clearance between the fan hub and the upper thrust washer assembly. The motorshaftis then moved downwardly to 'causethe' fan .hub 74 to engage the upper thrust washer and act'as the thrust stop therefor. play of the motor shaft.

When the machine is in normal operation, the centrifugal clutch couples the motor shaft to the motor pinion, and there is no relative motion therebetween. Relative motion occurs between the motor shaft and the motor pinion only in starting the machine or upon stalling of the brush while the motor is running. Upon starting the machine, the motor starts under no load and rapidly accelerates to the desired normal operating speed. When the motor speed reaches about2600 R. P. M. the clutch weights ily outwardly against the action of the garter spring firmly to engage the lining of the clutch cup and thus couple the motor shaft to the motor pinion.

This provides for the proper end .in the normal operation of the machine the motor runs at The motor pinion 153 meshes with a large diameter gear 192 of a cluster gear also having a gear of smaller diameter :193. This cluster gear is rotatably carried on 'a shaft 194 which in turn is secured to .a cluster gear bracketl95, ithe'bracket being adjustably secured to the lower side of the upper wall 12 of the base member.

The cluster gear is illustrated in more detail in Figs. 37 to 39 and includes a body portion 197 which may be formed of die cast zinc. The upper surface of the body portion 197 is provided with an annular boss 198 and also with a plurality of circumferentially spaced circular bosses 199. The gear 192 is formed on a tire of suitable plastic material such as nylon, the tire being provided with a central opening 290 and a plurality of holes 2131. The tire is placed on the upper surface of the body portion 197 with the central opening 200 engaging the annular boss 198 and with the holes 291 receiving the bosses 199. In this way a driving relationship is established between the tire and the body portion. A plate 2113 having a central opening and holes '204 is provided for clamping the tire in place on the body portion. ln'this respect rivets 205 extend through the holes 2% and through holes in .the'bosses 199. The inner part of the plateIZiiS rests on an annular shoulder 292 formedon the upper side of the body portion 197.

The body portion 197 has an extension or shank of reduced diameter upon which is mounted the gear 193, the gear being made of suitable plastic such as nylon. The body portion 197 is provided with aplurality of proiecti'ons'2tl7 extending between the gear teeth on the gear 193. These projectionsZ-fii provide a driving'con- 'neetion between the body portion 197 and the gear 193. 'T'hejgear 193 is provided with an internal recess 2% for receiving a washer 299 which in turn is held in place by peening over at 216' the lowerextremity of the body portion 197. In this way the gear 193 islocked in place on the body portion 197.

'A sintere'd porous bronze bearing 213 is securedwithin the body portion 197 and it seats against an internal shoulder 212. -An absorbent washer 214 rests against the upper surface of the porous bearing 213 and the absorb'ent washer is held in place by a metal washer 215, the metal washer in turn being staked in place as illustrated at 216. The absorbent washer is impregnated with a suitable lubricant for supplying lubricant to the porous bearing 213 for lubricating the running 'fit between the porous bearing and the cluster gear shaft 194.

The washer 215 in addition to encasing the absorbent washer 21.4.also acts as a thrust washer for the cluster gear.

In forming thecluster gear the smaller diameter plastic gear 193 has its teeth molded or othe wise formed'thereon before the gear is applied to the body portion. However, in the case ofthe larger diameter gear 192, the plastic tire in blank form is first secured to the body portion and then the gear teeth are suitablyhobbed or cut after assembly about a center corresponding to theaxis of'the porous bearing. This assures an accurate relation between the central axis of the cluster gear and the teeth of thelarger gear 192. The gear teeth may thus be accurately and-rapidly formed with small expense in this manner.

The cluster gear is rotatably mounted on the shaft 194 which in turn is provided at its upper end with a shoulder engaging the bracket 195, the shaft being held in place on the bracket 195 by peeningover the upper end thereof as at 218. A resilient thrust washer 220 preferably made of'impregnated cork is located between the bracket 1% andzthe washer 215. There is thus provided a resilientthrust bearing for the cluster gear. The bracket 195 is adjustably secured to the base member by screws 219 which extend through elongated slots 219a provided in the bracket. It will be appreciated that the slots 219a enable the bracket to be adjusted toward and away from the motor pinion.

Preferablyithe gear teeth of the motor pinion153 and the gear teeth of the gear 192 of the cluster gear are he'lically formed for the purpose of maintaining sub- 13 stantially constant thrust on the motor shaft and on the cluster gear. The direction or" the helices is such that upon operation of the machine a downward thrust is provided on the motor shaft and an upward thrust on the cluster gear. This upward thrust is absorbed by the resilient upper thrust bearing of the cluster gear.

The smaller gear 193 of the cluster gear meshes with an output gear 225 which is rotatably mounted on a shaft 226, the shaft being carried by a bracket 227 adjustably secured to the lower side or" the upper wall 12 of the base member.

The output gear 225 is illustrated in more detail in Figs. 4-0 to 42. The output gear includes a tire formed of suitable plastic material such as nylon in which the gear teeth are formed. It also includes a body portion 229 for carrying the tire. The body portion 229 may be formed of die cast zinc and is provided with an ex ternal shoulder 23% received in a groove formed in the lower side of the tire. The tire is provided with an internal surface 232 engaging the exterior of the body portion 229 and the body portion is provided with a plurality of lugs 23 received in notches 233 in the tire. in this way a driving connection is provided between the tire and the body portion. The top of the body portion 229 is provided with a plurality of circular bosses 234 which are received in holes 235 in a clamping disc 236. The outer edge of the clamping disc 236 is provided with a downwardly extending flange 237 received in a suitable groove in the tire. The disc 236 is fastened to the body portion 229 by peening over the bosses 234 as indicated at 232 and also securely clamps the tire in place on the body portion. The upper surface of the body portion is provided with an annular groove 24s) in which is received an absorbent washer 241 impregnated with suitable lubricant. The disc 236 partially overlies the absorbent washer for retaining the same in the annular groove. A sintered porous bronze bearing 242 is carried by the body portion 229 and it is provided with an annular flange 243 which also partially overlies the absorbent washer 241. The absorbent washer 241 supplies lubricant to the porous bearing 242 for lubricating the running fit between the caring and the shaft 226. The flange 243 on the upper end of the bearing 242 also serves as a thrust surface for the output gear and the thrust surface must be normal to the axis of rotation of r the output gear. To obtain the desired accuracy a shouldered punch is pressed into the bore of the bearing 213 with an interference fit until the shoulder strikes the flange for sizing the bore and squaring the flange. Then the bearing and punch are pressed into place with an interference lit for accurately locating the bearing in the body portion. Then the punch is removed from the hearing.

The body portion 229 is provided with a pair of holes 2 .5 and likewise the disc 236 is provided with a pair of holes 246, these holes receiving a pair of downwardly projecting pins 247 which are riveted in place as indicated at 243. These downwardly extending pins 247 are provided with enlarged heads having a conical surface 249 and a bead 259. These pins provide means for removably securing a brush to the output gear and also provide addii tional means for fastening the disc 236 to the body portion 229 for clamping the tire in place.

The bracket 227 is illustrated in Figs. 5, 1i and 13. It includes a plurality of legs 252 terminating in attaching ears 253 having slots 254. The slots 254 permit adjustment of the bracket 227 for the purpose set forth below. The bracket is secured to the base member by screws 255 and nuts 256, the screws 255 passing through the slots 254 and suitable holes in the base member. The lower surface of the bracket 227 has a plate 257 secured or welded thereto as indicated at 253. The shaft 226 is provided with a shoulder resting against the plate 257 and is held in place on the bracket by peening over the upper end of the shaft as indicated at 26$. A thrust washer assembly is interposed between the disc 257 and the output gear bearing flange 243. This thrust bearing assembly includes a metal cup-shaped member 262 having a running engagement with the porous bearing flange- 243 and a resilient washer 261 carried within the cupshaped member 262. The resilient Washer forms a resilient thrust bearing for the output gear. The lower end of the shaft 226 is provided with an annular groove 263 for receiving a split washer 264 for holding the output gear in place on the shaft 226. The lower side of the output gear is provided with a cover 265 for onclosing the output gear bearing 242 and the shaft 226 to prevent dirt and foreign material from going into the hearing.

The plate 257 overlies the disc 236 and is spaced a slight distance therefrom. The plate 257 acts as a stop for the output gear to prevent undue tilting of the out put gear with respect to the machine. The spacing be tween the plate 257 and the output gear disc 236 is such that the parts are not strained or stressed beyond their elastic limits when and if tilting should occur.

The output gear bracket 227 is provided with an extension 267 terminating in an car 269 provided with a hole 270. An opening 268 is also provided in the extension 267. The extension 267 and car 269 form an outboard support for the cluster gear shaft 194. In this respect a thrust washer 271 of fiber or other suitable material is interposed between the cluster gear and the car 269. A screw 272 is received in the lower end of the cluster gear shaft 194 for anchoring the same to car 269 of the bracket 227. The elongated hole or slot 270 in the extension 267 enables the brackets and 227 to be adjusted relative to each other. The opening 268 in the extension 267 is for accommodating the gears 193 and 225 so that these gears may mesh through that opening.

The gear teeth of the gears 193 and 225 are conven tional in form and preferably the gear teeth of the gear 225 are also cut or bobbed in the plastic tire after the tire has been secured in place on the body portion 229. This provides for accurate and inexpensive formation of the gear.

In assembling the gearing enclosed within the inverted cup-shaped base member 11, the gear 192 is first brought into proper meshing relation with the motor pinion 153 and then the supporting bracket 195 is securely fastened in place on the base member. Then the output gear 225 is brought into proper meshing relation with the cluster gear 193 and the supporting bracket 227 is then tightly secured to the base member. Since the brackets 195 and 227 are adjustably mounted in the manner described, it will be appreciated that the gears may be easily positioned in the manner just described to insure correct meshing of the gearing. Thus, the maintenance of close tolerance in the parts is not required.

In Fig. 12 there is illustrated another form of supporting bracket for the output gear shaft 22 in this arrangement a cup-shaped member 275 welded 2'76- to the bottom of the racket 227. A spacer 27' is interposed between the cup-shaped member 275 and the bracket 227. The shaft 226 is provided with a shoulder 278 engaging the cup-shaped member 275 and with shoulder 27 engaging the bracket 227. The shaft 226 is held in place by peening over the upper end thereof as indicated at This manner of mounting the output gear shaft 226 is more rig. than the other manner heretofore described and in this form there is no necessity for the stop plate 257.

Brush The output gear detachably carries a rotatable brush. This brush includes a brush backing 285 carrying a plurality of rows of brush bristles 236. The brush backing 285 of annular form is secured to a sheet metal disc 287 by means of rivets 228. The disc 287 has an annular surface 289 for engaging an annular shoulder 290 on tbs amu es r- The d sfl Provid d wi h a P o annularly arranged slots 292 of keyhole configuration. The larger opening 293 of the slots 292 are adapted to receive the enlarged heads of the pins 247 carried by the output gear. The smaller portions of the keyhole slots are bent upwardly at 294 at an angle corresponding to the conical portion 249 of the enlarged heads of the pins 247. Fig. 9 illustrates the brush in a position wherein the enlarged heads of the pins 247 have been inserted through the enlarged openings 293 of the keyhole slots. When the brush is rotated in the direction of normal rotation of the brush, the pins 247 enter the smaller portions of the keyhole slots and the conical surfaces on the enlarged heads of the pins cooperate with the tapered portions 294 of the keyhole slots for drawing the seating surface 289 of the brush disc into tight relation with the annular flange 296 on the output gear and this tight relation is maintained by the rotation of the brush. To prevent wobbiing of the brush with respect to the output gear, the annular flange 29% of the output gear is provided with a pair of recesses 2% adjacent the pins 247. If any irregularity should appear in the. seating surface 239 by reason of the formation of the keyhole slots, these irregularities are compensated for by the recesses 298 and tight seating of the disc 287 against the annular flange 290 is assured.

To hold the brush in position on the output gear when the brush is not being driven by the machine, there is provided a spring 295 for engaging one of the enlarged heads of the pins carried by the output gear to hold the same in the smaller portion of the keyhole slots, as illustrated in Fig. 10. The spring 295 is secured at its ends in holes 296 formed in the disc 287 and extends inwardly into engagement with the pin 247 through a hole 297 in the disc 287. The spring 295 operates as a detent and to move the brush from the position shown Fig. 9 to that shown in Fig. 10, and vice versa, all that is necessary is to give the brush a sharp twist which will overcome the detent action of the spring.

Since the entire machine is supported by the rotatable brush, the brush must be accurately made and accurately mounted on the output gcarand any inaccuracies in this respect may cause wobbling of the machine when in operation. To obtain maximum polishing efiicienc the brush bristles 2% are preferably arranged in three annular rows. Also, the brush bristles preferably extend outwardly and downwardly as illustrated to provide maximum stability for the machine. The gearing is such that when the motor is operating at its normal operating speed speed of 3300 R. P. M the brush rotates at a speed of approximately 220 R. P. M.

Handle structure The machine is manipulated by a handle Siiii having an attaching bail 3% which in turn is pivotally mounted to the sidewall 11 of the base member. The handle is adapted to be raised and lowered between a horizontal position and a position just beyond vertical. The pivotal. mounting for the handle bail 301 is illustrated in more detail in Figs. 6, 7 and 8. The handle bail 391 is channel-shaped and has a not 3%2 welded in each end thereof at 363. The not has a shank portion which extends through a hole in the side wall 11 of the base member for pivotaily mounting he bail on the base member. interposed between the nut 3&2 and the base member side Wall .13. is a friction washer Sit-4 for the purpose of restraining relative movement between the base member and the bail. A spring member 3'65 of generally cylindrical configuration overlies the inner end of the sh nk portion. of the .nut The corners of the spring member 305 engage the inner surface of the side wall it of the base member and this latter engagement operates to prevent rotation of the spring member 3% with respect to the base member. A screw 356 is screw threadedly received in the not 392 and the head of the screw 306 presses againstthe spring member 3%. By adjusting the screw 395, the amount of spring efiort produced by the spring member 305 may be regulated. Since the amount of friction of the friction washer 334i is dependent npon the tensioning eifect of the spring member 395, the friction of the. spring washer may be varied by adjusting the screw Bil-6 with respect to the out 392. When the proper adjustment is obtained, a plate 397 having a hexagonal hole therein is placed over the screw head 3%. The plate 3il7 and the spring member 305 are provided with a pair of holes for receiving resilient fasteners 3% which lock the plate 307 and hence the screw see against rotation. The direction of the screw threads of the screws 3% is such that when the handle and bail are moved from a vertical position to a horizontal position, the friction of the washer 3% becomes greater and likewise when the handle is raised from the horizontal position to the vertical position, the friction is decreased. By reason of this feature of automatically adjusting the friction coupling between the handle bail and the machine as the handle is raised and lowered, the machine may be readily manipulated in desired directions with little or no oscillation or gyration and with the least amount of control efiort applied to the grip portion of the handle.

The handle 3% is preferably hollow and it receives a conventional electrical extension cord 312 by means of which electrical energy is supplied to the motor in the machine. The supply of electrical energy may be regulated by a switch 311. The extension cord enters through a hole 313 in the side wall 11 of the base member and passes through a hole 314 in the upper wall 12 of the base member to the terminals on the phasing reactor. The extension cord 312 is held in place by a suitable clamp 315 carried by the stud 169. The handle may be provided with suitable brackets 3116 upon which the extension cord 312 may be wound.

The portion of the bail where the handle is attached thereto is provided with an ear 310 which engages the stop 1% on the top of the cover when the handle is raised just beyond the vertical position as illustrated in dotted lines in Fig. 1. This permits the handle to be maintained in the raised position and also permits carrying of the machine by the handle with the machine in its normal horizontal position.

The manner of ventilating and cooling the motor and building up a positive air pressure in the base member is claimed in application Serial No. 197,724, filed by William H. Kitto and Kurt Burian on November 27, 1950. The construction of the gearing between the motor shaft and the brush is claimed in application Serial No. 197,721, filed by William H. Kitto, on November 27, 1959. The construction of the electric motor is claimed in application Serial No. 197,723, filed by Kurt Burian, on November 27, 1950, now Patent 2,716,724, issued Aug. 30, 1955. The construction of the centrifugal clutch is claimed in application Serial No. 197,722, filed by William H. Kitto on November 27, 1950, now Patent 2,730,219, issued Jan. 10, 1956.

While for purposes of illustration one form of this invention has been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure and, therefore, this invention is to be limited only by the-scope of the appended claims.

We claim as our invention:

1. in a fioor polishing and scrubbing machine comprising, a base member having an opening therein, and a motor including a stator and a rotor having a shaft extending through the opening in the base member, the cornbination including a split band having ears provided with holes for clamping the motor stator, a plurality of legs connected with said band for attaching the band to the base member, a nut member having projections extending inwardly of the band for overlying the motor stator, and screws extending through the holes in the ears of the split band and nut member for in place.

2. In a floor polishing and scrubbing machine comprising a base member having an opening therein, and a motor including a stator and a rotor having a shaft extending through the opening in the base member, mtor stator support means including a band for clamping the motor stator, a plurality of legs connected with said band for attaching the band to the base member, and means for drawing up the band for clamping the stator in place with respect to the base member, said legs being lanced to provide lugs for overlying the motor stator to prevent longitudinal movement of the stator.

3. In a fioor polishing and scrubbing machine comprising, a base member having a bearing seat, and a motor stator, motor stator support means including a band for clamping the motor stator, a plurality of downwardly extending legs attached to the base member and a plurality of upwardly extending legs connected with said band, a bearing support plate having a bearing seat and attached to said upwardly extending legs, means for drawing up the band for clamping the motor stator in place with respect to the base member, a motor rotor having a shaft extending through the base member and the bearing support plate, and bearings seating in said bearing seats for journaling the motor rotor shaft.

4. In a floor polishing and scrubbing machine comprising, a base member having a bearing seat, a motor stator, and a motor rotor, a motor stator support member including a split band having ears provided with holes for clamping the motor stator, a plurality of downwardly extending legs attached to the base member and a plurality of upwardly extending legs connected with said downwardly extending legs, a bearing support plate having a bearing seat and attached to said upwardly extending legs, a nut member having projections overlying the motor stator, screws extending through the holes in the ears of the split band and nut member for clamping the stator in place, said motor rotor having a shaft extending through the base member and the bearing support plate, and bearings seating in said bearing seats for journaling the motor rotor shaft.

5. in a floor polishing and scrubbing machine comprising, a base member having a bearing seat, a motor stator, and a motor rotor, the combination including a band for clamping the motor stator, a plurality of downwardly extending legs connected to said band for attaching said band to the base member and a plurality of upwardly extending legs connected to said band, a bearing support plate having a bearing seat and attached to said upwardly extending legs, means for drawing up the band for clamping the motor stator in place with respect to the base member, said motor rotor having a shaft extending through the base member and the bearing support plate, and bearings seating in said bearing seats for journaling the motor rotor shaft, said legs being lanced to provide lugs overlying the motor stator to prevent longitudinal movement of the stator.

. In a floor polishing and scrubbing machine comprising, a base member, a motor including a stator and a rotor having a shaft, a motor supporting member attached to the upper side of the base member for supporting the motor above the base member with the rotor shaft extending through the base member, and a motor pinion located below the base member and driven by the motor shaft, the combination including a cluster gear meshing with the motor pinion, a generally vertically disposed cluster gear shaft carrying the cluster gear below the base member, an output gear meshing with the cluster gear, an output gear shaft carrying the output gear below the base member, bracket means attached to the lower side of the base member carrying the cluster gear shaft and the output gear shaft, a floor working brush having an annular body portion, the lower end of said cluster clamping the stator gear and said output gear being at least partially disposed within the annular body of the brush, and means for attaching the brush to the output gear.

7. A floor polishing and scrubbing machine comprising, a base member, a generally vertically disposed motor including a stator and a rotor having a shaft, a motor supporting member attached to the upper side of the base member for supporting the motor above the base member with the rotor shaft extending through the base member, a phasing reactor carried by the upper side of the base member and behind the motor, a cove enclosing the motor, motor supporting member and phasing reactor and attached to the upper side of the base member, a motor pinion located below the base member and driven by the motor shaft, a cluster gear meshing with and disposed behind the motor pinion, a cluster gear shaft carrying the cluster gear below the base member, an output gear meshing with the cluster gear, an output gear shaft carrying the output gear below the base member, bracket means attached to the lower side of the base member carrying the cluster gear shaft and the output gear shaft, a floor working brush disposed substantially concentrically with respect to the motor, means for attaching the brush to the output gear, a handle having a bail, and means for attaching the bail to opposite sides of the base member at points located substantially within a common plane extending through the motor axis.

8. In a floor polishing and scrubbing machine comprising, a base member having a spherical bearing seat, a motor stator, and a motor rotor, the combination including a motor stator support member for supporting the motor stator, means for adjustably securing the motor stator support member to the base member, a bearing support plate having a spherical bearing seat, means for adjustably securing the bearing support plate to the motor stator support member, said motor rotor having a shaft extending through the base member and the bearing support plate at the spherical bearing seats, and bearings having spherical seating surfaces engaging the spherical bearing seats for journaling the rotor shaft, the arrangement being such that the motor rotor may be temporarily shimmed with respect to the motor stator for centering the same and then the adjustable securing means for the motor stator support member and the bearing support plate may be tightened for maintaining the centered relation between the motor rotor and the motor stator when the shims are removed.

9. In a floor polishing and scrubbing machine comprising, a base member having a spherical bearing seat, a motor stator, and a motor rotor, the combination including a motor stator support member for supporting the motor stator, means for adjustably securing the motor stator support member to the base member, a bearing support plate having a spherical bearing seat, means for adjustably securing the bearing support plate to the motor stator support member, said motor rotor having a shaft extending through the base member and the bearing support plate at the spherical bearing seats, stationary bearings having spherical seating surfaces engaging the spherical bearing seats for journaling the rotor shaft, a metal thrust Washer running against each stationary bearing, a resilient washer in contact with each metal washer, and a cup shaped member tightly enclosing each resilient washer for frictionally coupling the resilient washers to the rotor shaft.

10. In a floor polishing and scrubbing machine comprising, a base member having a spherical bearing seat, a motor stator, a motor stator support member for supporting the motor stator, means for adjustably securing the motor stator support member to the base member, a bearing support plate having a spherical bearing seat, and means for adjustably securing the bearing support plate to the motor stator support member, the combination comprising a substantially vertically disposed motor rotor having a shaft extending through the base member and the bearing support plate at the spherical bearing seats, stationary bearings having spherical. seating surfaces engaging the spherical bearing seats for iournaling the rotor shaft, ametal thrust washer running a ainst each stationary bearing, a re iiient washer in contact with each metal washer, a cup shaped member tightly enclosing each resilient washer for frictionally coupling the resilient washers to the rotor shaft, and a fan a iustably secured to the rotor shaft adjacent the upper cup shaped. member and providing an adjustable thrust stop for the rotor shaft.

11. In a floor polishing and scrubbing machine comprising a base member, a motor stator, a motor stator support member for supporting the motor stator and secured'to the base member, and a bearing support plate secured to the motor stator support member, the combination including a motor rotor having a shaft extending through the base member and the bearing support plate, bearings carried by the base member and the support plate for journaling the motor rotor shaft, a thrust bearing longitudinally slidably carried by the rotor shaft and running against the bearing carried by said bearing support plate, and a fan adjustably secured to the rotor shaft adjacent the thrust bearing and providing an adjustable thrust stop for the rotor shaft.

12. In a floor polishing and scrubbing machine comprising, a base member, a motor stator, a motor stator support member for supporting the motor stator and secured to the base member, and a bearing support plate secured to the motor stator support member, the combination including a motor rotor having a shaft extending through the base member and the bearing support plate, bearings carried by the base member and the bearing support plate for journaling the motor rotor shaft, a metal thrust washer running against the bearing carried by said bearing support plate, a resilient washer in contact with the metal washer, and a cup shaped member tightly enclosing the resilient washer for frictionally coupling the resilient washer to the rotor shaft.

13. In a floor polishing and scrubbing machine comprising, a base member, a motor stator, a motor stator support member for supporting the motor stator and secured to the base member, and a bearing support plate secured to the motor stator support member, the combination including a motor rotor having a shaft extending through the base member and the bearing support plate, bearings carried by the base member and the bearing support plate for journaling the motor rotor shaft, 0. metal thrust washer running against the bearing carried by said bearing support plate, a resilient washer in contact with the metal washer, a cup shaped member tightly enclosing the resilient washer for frictionally coupling the resilient washer to the rotor shaft, and a fan adiustably secured to the rotor shaft adjacent the cup shaped member and providing an adjustable thrust stop for the rotor shaft.

14. In a polishing and scrubbing machine, a atable brush supporting member, a supporting bracket, a cupped washer adjacent said bracket, a yieldable spacer member between the bracket and the cupped washer, a shouldered shaft riveted through the washer, spacer member and bracket, said yieldable spacer member facilitating slight tilting movement of the bracket relative to the shaft and means for rotatably mounting the brush supporting member on the shaft.

15. In a polishing and scrubbing machine, a rotatable brush supporting member, a supporting bracket, a shaft pendantly attached to the bracket, a resilient washer fitting snugly on said shaft and against said bracket, a cupped washer fitting over the resilient washer, an end surface of said cupped washer being flat, a flanged bearing carrying the brush supporting member and mounted for rotation on the shaft and having its flange engaging the'flat surface of the cupped washer for carrying the thrust load, said brush supporting member having one 253 surface substantially parallel to and uniformly spaced a predetermined distance from said supporting bracket to limit any tilting movement of the brush supporting memher with respect to the bracket.

16. A floor polishing and scrubbing machine comprising a frame, a brush rotatable about an axis perpendicular to the floor, means for rotating the brush, a handle including a bail for manipulating the machine, means for pivotally mounting the bail to the frame to provide movement of the handle between a horizontal and a vertical position, friction means for resisting relative movement between the frame and the handle, and means operable on said friction means for increasing resistance to relative movement between the handle and the frame as the handle is moved from the vertical position to the horizontal position and for decreasing resistance to relative movement between the frame and the handle as the handle is moved from the horizontal position toward the vertical position.

17. A floor polishing and scrubbing machine comprising a frame, a brush rotatable about an axis perpendicular to the floor, means for rotating the brush, a handle including a bail for manipulating the machine, means for pivotally mountin the bail to the frame to provide movement of the handle between a horizontal and a vertical position, said last mentioned means including a nut carried by and fixed relative to te bail, a friction washer between the nut and the frame for resisting relative movement between the frame and the handle and a screw normally held stationary with respect to the frame and screw threadedly received in the nut for applying increased clamp'mg pressure to the friction washer as the handle is moved from the vertical position to the horizontal position and for decreasing the clamping pressure as the handle is moved from the horizontal position toward the vertical position.

18. A floor polishing and scrubbing machine comprising, a frame, a brush rotatable about an axis perpendicular to the floor, means for rotating the brush, handle including a bail for manipulating the machine, means for pivotally mounting the bail to the frame to provide movemerit of the handle between a horizontal and a vertical position, said last mentioned means including a nut carried by and fixed relative to the bail, a friction washer between the nut and the frame for resisting relative movement between the frame and the handle, a screw received in the nut, a spring between the screw and the frame for resiliently clamping the friction washer between the nut and the frame, and means for normally preventing rotation of the screw for increasing the clamping pressure on the friction washer as the handle is moved from the vertical position to the horizontal position and for decreasing the clamping ressure as the handle is moved from the horizontal position toward the vertical position.

19. in a floor polishing and scrubbing machine, a motor including a motor shaft, a resilient thrust bearing for the motor shaft, a motor pinion driven by the motor shaft, gearing for connecting the motor pinion and a floor working brush including an intermediate cluster gear meshing with the motor pinion, and a resilient thrust bearing for the intermediate cluster gear, the engaging teeth on the motor pinion and intermediate cluster gear being helically formed to produce during operation of the machine a thrust force on the motor shaft against its resilient thrust bearing and a thrust force on the intermediate gear against its resilient thrust bearing.

20. In a floor polishing and scrubbing machine, a base member, a motor carried by the base member and having a motor shaft, a pinion driven by the motor shaft, :1 cluster gear meshing with the motor pinion, a cluster gear shaft carrying the cluster gear, a cluster gear bracket carrying the cluster gear shaft, means for adjustably securing the cluster gear bracket to the base member for properly meshing the cluster gear with the motor pinion, an output gear meshing with the cluster gear, anoutput near shaft carrying the output gear, a separate output gear bracket carrying the output gear, and means for adjustably securing the output gear bracket to the base member for properly meshing the output gear with the cluster gear.

21. in a floor polishing and scrubbing machine, a base member, a motor carried by the base member and having a motor shaft, a pinion driven by the motor shaft, a cluster gear meshing With the motor pinion, a cluster gear shaft carrying the cluster gear, a cluster gear bracket carrying the cluster gear shaft, means for adjustably securing the cluster gear bracket to the base member for properly meshing the cluster gear With the motor pinion, an output gear meshing with the cluster gear, an output gear shaft carrying the output gear, separate output gear bracket carrying the output gear, and means for adjustably securing the output gear bracket to the base member for properly meshing the output gear with the cluster gear, an extension on the output gear bracket, and means for securing the extension on the output gear bracket to the cluster gear shaft to form a further support for the cluster gear shaft.

22. in a floor polishing and scrubbing machine, a base member, a motor carried by the base member and having a motor shaft, a pinion driven by the motor shaft, a cluster gear meshing with the motor pinion, a cluster gear shaft carrying the cluster gear, a cluster gear bracket, means for securing one end of the cluster gear shaft to the cluster gear bracket, means for adjustably securing the cluster gear bracket to the base member for properly meshing the cluster gear with the motor pinion, an output gear meshing with the cluster gear, an output gear shaft carrying the output gear, a separate output gear bracket, means for securing one end of the output gear shaft to the output gear bracket, and means for adjustably securing the output gear bracket to the base member for properly meshing the output gear with the cluster gear.

23. In a floor polishing and scrubbing machine, a base member, a motor carried by the base member and having a motor shaft, a pinion driven by the motor shaft, a cluster gear meshing with the motor pinion, a cluster gear shaft carrying the cluster gear, a cluster gear bracket, means for securing one end of the cluster gear shaft to the cluster gear bracket, means for adjustably securing the cluster gear bracket to the base member for properly meshing the cluster gear with the motor pinion, an output gear meshing with the cluster gear, a separate output gear shaft carrying the output gear, an output gear bracket, means for securing one end of the output shaft to the output gear bracket, and means for adjustably securing the output gear bracket to the base member for properly meshing the output gear with the cluster gear, an extension on the output gear bracket, and means for securing the other end of the cluster gear shaft to the extension on the output gear bracket to form an outboard support for the cluster gear shaft.

24. In a floor polishing and scrubbing machine, a supporting bracket, a shaft carried by the bracket and having a groove at its outer end, an output gear having a hub, a bearing member carried by the output gear for journaling the output gear for rotation on the shaft, a thrust bearing between the supporting bracket and the output gear, a ring carried by the groove in the shaft for retaining the output gear on the shaft, means on the output gear for detachably connecting an annular brush thereto, and a cup shaped member secured over the end of the output gear hub to exclude dirt from the bearing member and to retain oil therein.

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